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How To Make Thunder Caps

For this project I’m going to show you how
to convert sticky labels and a couple of matches into a handful of exploding stickers. Put
them on a hard surface and hit them with a hammer, and they explode on impact with enough
power to leave your ears ringing. These little “Thunder Caps” are super cheap and easy
to make, and are a fun way to level up your target practice as well. Because with “Thunder
Caps”, your targets explode. All we need to start this project is a box
of safety matches, and a razor blade. The box-cutter I’m using has a quick release
feature for removing the blade inside, and that’s what I’ll be using in a couple
of minutes. Now let’s get to work making our improvised
cap gun powder, with the heads of two safety matches. Matches like these are around 50% Potassium
Chlorate, mixed with a few other ingredients like sulfur, starch, and glue. If we take a hammer and lightly tap the heads
of the matches, while slowly rolling the sticks around, you can see the pyrotechnic shell
separates from the stick, and flakes right off. You might have noticed I’m collecting the
match heads on a paper sticky note, and that’s mainly to help keep my brick clean, but it’ll
also make it a lot easier to capture and transfer the powder, later on. Now our “Thunder Caps” are going to make
a much bigger bang if we grind the chunks down into a really fine powder. And a really
easy way to do that with a kitchen knife. Crush them with the blade, then carefully
spread the powder back and forth a few times, like you’re putting butter on a muffin. In less than a minute, you’ll find you have
an extremely fine match-head powder, that should look something like this. Alright it’s time for the second ingredient,
that makes all the explosive magic happen. And you’ll find it right there, on the side
of your matchbox. Take your razor blade, and slowly and carefully,
begin scraping the side of the box so you can harvest some of the fine red powder. And
keep a sticky note, or a piece of paper under the box so you salvage as much of it as possible. This precious powder is about 50% red phosphorous,
mixed with a few other abrasive materials, like powdered glass. Use your blade to carefully scrape the 2 powders
into separate lines, but make sure they don’t mix together yet. Because if they do, they’ll
activate, and become come “impact sensitive”. The recipe I’m using for my cap gun mix
is 2 parts powdered match-heads to 1 part “striker strip” powder. So as a basic rule of thumb, just make sure
your green line is twice as long as the red one, and it should work just fine. The safest and easiest way I’ve found for
mixing the two powders, is by dropping them into a plastic party cup, and carefully swirling
the mixture around for about 20-30 seconds. This way the composition gets thoroughly mixed,
and there’s very little risk of spontaneous ignition. But that doesn’t mean it won’t
ignite. In fact you should always treat your cap powder
with the highest levels of caution and respect, to avoid setting it off accidentally. Now hopefully you’ve got some ear plugs
and safety glasses nearby, because the time has come, to bust some caps. Watch closely as I smack the tiny pile with
a hammer, and you’ll see the instant it makes contact, the power explodes, and vaporizes
into thin air. If you don’t have a hammer, it’s no problem.
You can actually set the powder off with anything that hits hard enough, to shock it. This amazing composition you’ve created
is an improvised version of “Armstrong’s Mixture”, which interestingly enough, is
the same powder used for making cap gun caps. So that means, now you have the option of
reloading old cap gun caps, and making them up to 10 times more powerful. Try using that option
with the “Exploding Cap Darts” we made in a previous video. Now just for fun, why don’t we take this
experiment one step further, with a pack of sticky dots. I found a bundle of over 300 sticky-backed
labels, from the stationary section of my local grocery store. Set one of the labels down on the table with
the sticky side facing up, then use something like a modified drinking straw to carefully
transfer a tiny bit of the cap powder, to the center of the label. Drop the powder right in the middle, then
find another sticker the same color, and carefully press it down overtop, sealing off the edges,
and trapping the powder inside. You’ve just created a powerful, homemade
“Smack Cap”. And if you look closely, you should be able to see the powder located
in the center, ready for action. I went ahead and made a whole bunch more by
adding the rest of the powder to different colored dots, using the color coding to my
advantage. The green dots have the smallest amount of
powder, The orange dots have around twice as much powder, and the pink dots are as full
as I could get them. Testing them out on my workbench it’s easy
to see the difference between the green, the orange, and the pink dot, which was actually
so loud, your ears would have been ringing. So remember to do the smart thing, and wear
ear plugs. I smacked a cap on a dirty brick, so you can
see the shockwave it makes, when it explodes, then put one of the orange dots inside a leaf
to see what would happen if we hit it with a rock. Apparently, the leaf gets completely
obliterated, in just an instant. For one final experiment I picked up a CO2
powered BB gun to see what would happen if we tried using our “Thunder caps” for
target practice. I printed off a paper target, and taped a
“Smack Cap” to the center, so when a pellet hits the bullseye, the target explodes. By sticking “Thunder Caps” to your targets,
you’ll get a very gratifying feeling, of power and accomplishment when you hit your
targets dead-on. These exploding dots aren’t just for BB
guns though. They can be used with slingshots, blow darts, and I imagine they’d probably
work with high speed air-soft pellets as well. But whichever way you use them, one thing
is for sure. You’re bound to get a reaction, each time you set one off. Well now you know how to use a couple of matches
and some sticky labels to make an arsenal of color coded “Thunder caps”. And whether you use them for target practice,
or just for having a bit of fun exploring science in the back yard, your “Thunder
Caps” are guaranteed to be a blast. Well that’s it for now. If you like this
project perhaps you’ll like some of my others. Check them out at

58 thoughts on “How To Make Thunder Caps

  1. This is just the best! People at night are stealing fruits from my fruit tree, I can just put these around the tree and BOOM, they run away!

  2. People in 2015: wow this is so cool ‘mum can I make this’

    People in 2019:I miss u so much ‘son what’s wrong’. ‘he’s dead’

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